It is known in the blasting industry to use initiation devices for initiating shock tube which, in turn, ignites a base charge. The shock tube contains a small quantity of gun powder that is ignited by a powerful percussion spark generated by the initiation device. The initiation of the gun powder causes the base charge coupled to the remote end of the shock tube to be ignited. This type of shock tube is commonly referred to as non-electric shock tube due to the fact that gun powder rather than electricity is used to ignite the base charge.
Conventional non-electric shock tube initiation devices used in the blasting industry include an initiator tip which contains electrical components for generating the spark that initiates the gun powder in the shock tube. The typical initiator tip comprises a standard coaxial cable connector and relies on generating a differential voltage between the inner conductor of the coaxial cable and the outer conductor of the coaxial cable to create the percussion spark.
One disadvantage of the conventional non-electric shock tube initiation device is that the inner electrode of the coaxial cable connector is comprised of copper, which is easily damaged by the high-temperatures produced by the percussion spark. Consequently, repeated firing of the initiation device destroys the tip of the inner electrode, which is housed in the initiator tip of the initiation device and which couples with the shock tube.
Another disadvantage of the conventional non-electric shock tube initiation device is that the coaxial cable connector that functions as the initiator tip is made of a conductive material. Therefore, if a person touches the initiator tip while current is being applied to the electrodes, the person will receive a high-voltage shock, thereby risking serious bodily injury and possibly death.
Accordingly, a need exists for an initiator tip for use with a non-electric shock tube initiation device which utilizes an inner electrode made of a relatively high-temperature conductive material that can withstand the high temperatures associated with firing the tip. A need also exists for an initiator tip which comprises an outer encasing made of an insulative material for eliminating the possibility of electric shock to a person using the initiation device.